Post by warspite1 on Jun 3, 2020 10:47:12 GMT
From the Warspite archives. First published on Forumini January 2011.
*** *** *** *** *** *** *** ***
In both world wars several nations armed their merchant ships as auxiliary warships. These included camouflaged 'Q-Ships' to surprise surfaced U-boats at close range; commerce raiders to prey on single merchant ships and armed merchant cruisers for patrol or blockade duty. One of the biggest users of the armed merchant cruiser (AMC) was the Royal Navy as it had the entire British and Empire merchant marine to call upon. In World War Two AMCs received a grim nickname based on these three initials - the seamen called them "Admiralty-Made Coffins". But how true was this nickname? Minimal research suggests that some AMCs could absorb a surprising degree of underwater damage and the consequential survival rate among the crews of sinking AMCs was quite high.
The Royal Navy had always feared an attack on shipping lanes as Britain depended on its foreign trade, it was the nation's lifeblood. Prior to both world wars there were plans to impress some of the larger merchant ships as patrol warships. From 1920 UK and Empire shipping lines were paid money to include strengthened hard points for guns during construction which would ease later auxiliary warship conversions. Even the majestic liners RMS Queen Mary and RMS Queen Elizabeth had these hard points incorporated into their plans. Thus both ships were armed in WW2 but served as fast moving troopships, sailing independently well away from the convoy routes to avoid U-boat attack.
In World War One the Royal Navy had early success with camouflaged Q-ships during the period when the Imperial German Navy still followed 'civilised' cruiser warfare rules and attacked on the surface, with gunfire, after giving the merchant crew enough time to abandon ship. A 'panic' crew would leave the Q-ship watched by the Germans and when the U-boat came within range and opened fire, a second - concealed - crew of gunners would collapse their camouflage aboard the Q-ship and open up with lquick-firing light artillery. In time, enough U-boat crews survived encounters with these 'first round' Q-ships for the word to get around and U-boat tactics changed.
When unrestricted U-boat warfare commenced later in WW1, and surprise submerged attacks became the norm, Royal Navy Q-ship tactics were adapted and the innocent-looking Q-ships now INVITED a sudden torpedo attack. The ships' holds had been filled with bundles of timber, wooden barrels, oil barrels - basically anything that would float and assist the ships' buoyancy. The plan was to get a Q-ship torpedoed, another panic crew then fled the ship but when the 'helpless' target did not sink the U-boat would be tempted to surface and use its deck gun for the coup-de-grace. Again the camouflage would be pulled aside and, again, the Q-ship's crew would open fire with light QF artillery. Sometimes it worked.
WW1 experience with keeping ships afloat in difficult circumstances stood the Royal Navy in good stead in WW2 and when the programme to convert new AMCs was commenced empty oil barrels were included 'tween decks in some ships together with a heavy cargo of ballast in the lowest part of the ship to prevent capsize. Conway's lists more than 55 ships as serving as RN, RCN or RAN AMCs in WW2. Some only served for short periods and most were later adapted to other purposes. A number were war losses. The most famous are HMS Jervis Bay and HMS Rawlapindi which both made heroic but hopeless stands against modern German warships and were destroyed by gunfire. I will be concentrating on the U-boat losses and the effectiveness of the 'oil barrel' anti-torpedo defence.
The following AMCs were sunk by U-boat:
HMS Andania: 13,950 tons
HMS Carinthia: 20,277 tons
HMS Dunvegan Castle: 15,007 tons
HMS Forfar: 16,402 tons
HMS Laurentic: 18,724 tons
HMS Patroclus: 11,314 tons
HMS Rajputana: 16,644 tons
HMS Salopian: 10,515 tons
HMS Scotstoun: 17,046 tons
HMS Transylvannia: 16,923 tons
Taking the same list, lets look at what sank them:
Andania: one torpedo hit, June 1940 and sank slowly by the stern. No casualities, 100% survivors.
www.uboat.net/allies/merchants/ships/355.html
Carinthia: one torpedo hit, June 1940, steamed in circles dropping depth charges and slowly burning, eventually developed a port list and sank. Four dead, majority survived.
www.uboat.net/allies/merchants/ship/338.html
Dunvegan Castle: three torpedo hits in three separate attacks in August 1940, she caught fire and eventually foundered the following day with many survivors
www.uboat.net/allies/merchants/ship/489.html
Forfar: five separate torpedo hits over more than an hour in December 1940, eventually sinking with the loss of the majority of the crew.
www.uboat.net/allies/merchants/ships/702.html
Laurentic: four torpedo hits in three attacks in November 1940, eventually sinking when part of the stern was blown off and sank first carrying fused depth charges. These also detonated. Despite massive damage, at night, around 90% of her crew survived.
sites.rootsweb.com/~cannf/mil_hmspatlau.htm
Patroclus: sunk the same night as Laurentic, six torpedo hits over more than five hours plus two shell hits from U-boat deck gun. 76 out of 300 men lost.
www.uboat.net/allies/warships/ship/3325.html
plus see Laurentic link above.
Rajputana: two torpedo hits in five attacks in April 1941, sank slowly with majority of survivors picked up.
www.uboat.net/allies/merchants/ships/876.html
Salopian: at least five hits in six separate attacks in May 1941. Ship eventually broke in two. Majority of crew rescued.
www.uboat.net/allies/warships/ship/3330.html
Scotstoun: two hits in two separate attacks in June 1940. Seven men lost, 345 survivors.
www.uboat.net/allies/merchants/ships/348.html
Transylvannia: only one hit in August 1940 due to attacking U-boat running out of torpedoes. Ship taken in tow but later foundered. Majority of crew rescued.
www.uboat.net/allies/merchants/ships/457.html
I am indebted to uboat.net for the majority of the above links.
Looking at the above list it is easy to see that there is a wide margin of difference in an individual AMC's performance when hit by a torpedo. HMS Patroclus, one of the smallest ships at just over 11,000 tons, managed to absorb six hits and two exploding shells before succumbing. On the other hand the 20,000 ton HMS Carinthia took just one hit and sank, albeit slowly. This leads me to the conclusion that the Admiralty's conversion of these vessels was uneven and not all ships received the full conversion package. In war-time one of the first things likely to be in short supply is good oil drums and I am tempted to conclude that the ships lost to just one or two torpedo hits were those ships which either did not receive any oil barrels or certainly did not receive enough.
This appears to be confirmed by naval constructor D.K. Brown in his book 'Nelson to Vanguard' (page 145) in which Brown explains that the Admiralty drew up an ideal plan in 1936, based on the blueprints of the P&O steamer Carthage. This provided for a three-stage refit. The first stage taking three weeks, the second five weeks and the last was for 10 weeks. "Each yard would use the Carthage plans as guidance for the work on their vessels. This preparatory work was well organised and the actual conversions went smoothly," said Brown. It is clear from the three-stage plan that it was expected that not every ship would receive 'stage 3' - it would depend on available facilities and materials were to be found at each home port.
First-stage conversion included fitting the guns - mostly ex-WW1 hand-worked 6-inch and some 3-inch AA guns - plus accommodation for around 230 RN personnel and the essential 1500 to 3000 tons of ballast. Second-stage conversion included some 1-inch thick armour plate, more modern guns and director firing (in just nine ships). Brown says that, later, empty oil drums were packed in the 'tween decks "to preserve buoyancy and stability' and he comments that this was so successful that of the 15 AMCs sunk, only one capsized. As readers will be aware capsize is a frequent result of a torpedo hit even on major warships such as HMS Royal Oak, HMS Barham or HMS Ark Royal. Just one in 15 losses therefore represents some considerable vindication of the heavy ballasting if not of the oil drums themselves. I assume from his phrasing that the oil drums were the third-stage so, in addition to availabilty, one has to factor-in the estimated 10 weeks it would take to do that work (see previous paragraph for time-to-completion).
On page 167 Brown reveals that the torpedoed (not lost) AMC HMS Cheshire was able to make six knots with two main holds flooded and a third slowly flooding. She got home successfully and was repaired in the remarkably short time of six weeks. Brown also reveals that the oil drum expedient was actually incorporated into the design of the Colossus Class light aircraft carriers. It would be interesting to know if these oil drums remained in the post-war Colossus Class when they served in the navies of France, Holland, Australia, Canada, Argentina and Brazil and whether they were still there when these venerable ships went to the breakers' yard. I wonder what the crew made of them?
That the oil drums came as a surprise to the Germans is discussed by Chris Paddock on his Patroclus and Laurentic website:
sites.rootsweb.com/~cannf/mil_hmspatlau.htm
"U-99 closed to within 300 yards without being spotted, and fired a torpedo, which struck Patroclus near the stern, immediately beneath a loaded lifeboat that was being hauled aboard. The lifeboat, the men aboard it, and a huge section of Patroclus' hull were blown to pieces. Kretschmer and his officers were astounded to see a large number of empty oil drums erupt from the ship's newly torn hull to bob like corks on the ocean swell. U-99 then fired another torpedo at the same section of Patroclus' hull."
Later...
"A large section of the forward well deck disintegrated, and several of Patroclus' crew vanished into the smoking void. Another volley of escaping oil drums confounded the U-boat's commander, and Kretschmer concluded, correctly, that they had been placed in Patroclus' hold in order to sustain the ship's buoyancy and survivability in the event of a torpedo attack. He further concluded that Laurentic's reluctance to sink was likely due to the same reason."
And...
"Otto Kretschmer, while returning U-99 to her patrol area, recorded in his log the curious use of the empty oil drums, stacked by the hundreds in the holds of the armed merchant cruisers, as a torpedo countermeasure. Ultimately it didn't save the ships, but it did force him to exhaust the lion's share of his torpedo supply to sink them. He would record a very similar incident less than a month later, when, on December 2nd, he attacked and sank another armed merchant cruiser, H.M.S. Forfar. Her holds were also jammed with oil drums, and it took 5 torpedoes to sink her."
Chris Paddock's whole page is worth a very careful read is it reveals that Otto Kretschmer had to carry out the double attack on Laurentic and Patroclus with a loitering Sunderland above him and a nearby enemy destroyer heading towards him.
While researching this I also had access to 'The Blockaders' by A Cecil Hampshire. On page 38 he confirms that timber and empty metal drums had already been added to RN AMCs in WW1 as a direct result of the clash between the AMC HMS Carmania and the German Cap Trafalgar in 1914.
Author Hampshire also refers to the oil drums and ballast, implying that all ships were outfitted with the oil drums which - as we have seen - is probably unlikely. He says the drums were: "Officially designated buoyancy ballast but dubbed by the crews 'ping-pong' balls to help keep the ship afloat in the event of her being torpedoed or mined."
Reviewing the evidence it is fairly clear that while the Admiralty AMC was clearly an extemporised warship and suffered from all the faults of being just that - extemporised. There was a high survival rate among the crews serving on them coupled-with the ability of several of the AMCs to absorb more torpedo hits than some WW2 battleships (HMS Royal Oak and HMS Barham were each sunk by only three torpedoes). All seamen love their little jokes but the 'Admiralty-Made Coffins' may be worthy of rather more respect, in hindsight, than they ever received during the war.
*** *** *** *** *** *** *** ***
In both world wars several nations armed their merchant ships as auxiliary warships. These included camouflaged 'Q-Ships' to surprise surfaced U-boats at close range; commerce raiders to prey on single merchant ships and armed merchant cruisers for patrol or blockade duty. One of the biggest users of the armed merchant cruiser (AMC) was the Royal Navy as it had the entire British and Empire merchant marine to call upon. In World War Two AMCs received a grim nickname based on these three initials - the seamen called them "Admiralty-Made Coffins". But how true was this nickname? Minimal research suggests that some AMCs could absorb a surprising degree of underwater damage and the consequential survival rate among the crews of sinking AMCs was quite high.
The Royal Navy had always feared an attack on shipping lanes as Britain depended on its foreign trade, it was the nation's lifeblood. Prior to both world wars there were plans to impress some of the larger merchant ships as patrol warships. From 1920 UK and Empire shipping lines were paid money to include strengthened hard points for guns during construction which would ease later auxiliary warship conversions. Even the majestic liners RMS Queen Mary and RMS Queen Elizabeth had these hard points incorporated into their plans. Thus both ships were armed in WW2 but served as fast moving troopships, sailing independently well away from the convoy routes to avoid U-boat attack.
In World War One the Royal Navy had early success with camouflaged Q-ships during the period when the Imperial German Navy still followed 'civilised' cruiser warfare rules and attacked on the surface, with gunfire, after giving the merchant crew enough time to abandon ship. A 'panic' crew would leave the Q-ship watched by the Germans and when the U-boat came within range and opened fire, a second - concealed - crew of gunners would collapse their camouflage aboard the Q-ship and open up with lquick-firing light artillery. In time, enough U-boat crews survived encounters with these 'first round' Q-ships for the word to get around and U-boat tactics changed.
When unrestricted U-boat warfare commenced later in WW1, and surprise submerged attacks became the norm, Royal Navy Q-ship tactics were adapted and the innocent-looking Q-ships now INVITED a sudden torpedo attack. The ships' holds had been filled with bundles of timber, wooden barrels, oil barrels - basically anything that would float and assist the ships' buoyancy. The plan was to get a Q-ship torpedoed, another panic crew then fled the ship but when the 'helpless' target did not sink the U-boat would be tempted to surface and use its deck gun for the coup-de-grace. Again the camouflage would be pulled aside and, again, the Q-ship's crew would open fire with light QF artillery. Sometimes it worked.
WW1 experience with keeping ships afloat in difficult circumstances stood the Royal Navy in good stead in WW2 and when the programme to convert new AMCs was commenced empty oil barrels were included 'tween decks in some ships together with a heavy cargo of ballast in the lowest part of the ship to prevent capsize. Conway's lists more than 55 ships as serving as RN, RCN or RAN AMCs in WW2. Some only served for short periods and most were later adapted to other purposes. A number were war losses. The most famous are HMS Jervis Bay and HMS Rawlapindi which both made heroic but hopeless stands against modern German warships and were destroyed by gunfire. I will be concentrating on the U-boat losses and the effectiveness of the 'oil barrel' anti-torpedo defence.
The following AMCs were sunk by U-boat:
HMS Andania: 13,950 tons
HMS Carinthia: 20,277 tons
HMS Dunvegan Castle: 15,007 tons
HMS Forfar: 16,402 tons
HMS Laurentic: 18,724 tons
HMS Patroclus: 11,314 tons
HMS Rajputana: 16,644 tons
HMS Salopian: 10,515 tons
HMS Scotstoun: 17,046 tons
HMS Transylvannia: 16,923 tons
Taking the same list, lets look at what sank them:
Andania: one torpedo hit, June 1940 and sank slowly by the stern. No casualities, 100% survivors.
www.uboat.net/allies/merchants/ships/355.html
Carinthia: one torpedo hit, June 1940, steamed in circles dropping depth charges and slowly burning, eventually developed a port list and sank. Four dead, majority survived.
www.uboat.net/allies/merchants/ship/338.html
Dunvegan Castle: three torpedo hits in three separate attacks in August 1940, she caught fire and eventually foundered the following day with many survivors
www.uboat.net/allies/merchants/ship/489.html
Forfar: five separate torpedo hits over more than an hour in December 1940, eventually sinking with the loss of the majority of the crew.
www.uboat.net/allies/merchants/ships/702.html
Laurentic: four torpedo hits in three attacks in November 1940, eventually sinking when part of the stern was blown off and sank first carrying fused depth charges. These also detonated. Despite massive damage, at night, around 90% of her crew survived.
sites.rootsweb.com/~cannf/mil_hmspatlau.htm
Patroclus: sunk the same night as Laurentic, six torpedo hits over more than five hours plus two shell hits from U-boat deck gun. 76 out of 300 men lost.
www.uboat.net/allies/warships/ship/3325.html
plus see Laurentic link above.
Rajputana: two torpedo hits in five attacks in April 1941, sank slowly with majority of survivors picked up.
www.uboat.net/allies/merchants/ships/876.html
Salopian: at least five hits in six separate attacks in May 1941. Ship eventually broke in two. Majority of crew rescued.
www.uboat.net/allies/warships/ship/3330.html
Scotstoun: two hits in two separate attacks in June 1940. Seven men lost, 345 survivors.
www.uboat.net/allies/merchants/ships/348.html
Transylvannia: only one hit in August 1940 due to attacking U-boat running out of torpedoes. Ship taken in tow but later foundered. Majority of crew rescued.
www.uboat.net/allies/merchants/ships/457.html
I am indebted to uboat.net for the majority of the above links.
Looking at the above list it is easy to see that there is a wide margin of difference in an individual AMC's performance when hit by a torpedo. HMS Patroclus, one of the smallest ships at just over 11,000 tons, managed to absorb six hits and two exploding shells before succumbing. On the other hand the 20,000 ton HMS Carinthia took just one hit and sank, albeit slowly. This leads me to the conclusion that the Admiralty's conversion of these vessels was uneven and not all ships received the full conversion package. In war-time one of the first things likely to be in short supply is good oil drums and I am tempted to conclude that the ships lost to just one or two torpedo hits were those ships which either did not receive any oil barrels or certainly did not receive enough.
This appears to be confirmed by naval constructor D.K. Brown in his book 'Nelson to Vanguard' (page 145) in which Brown explains that the Admiralty drew up an ideal plan in 1936, based on the blueprints of the P&O steamer Carthage. This provided for a three-stage refit. The first stage taking three weeks, the second five weeks and the last was for 10 weeks. "Each yard would use the Carthage plans as guidance for the work on their vessels. This preparatory work was well organised and the actual conversions went smoothly," said Brown. It is clear from the three-stage plan that it was expected that not every ship would receive 'stage 3' - it would depend on available facilities and materials were to be found at each home port.
First-stage conversion included fitting the guns - mostly ex-WW1 hand-worked 6-inch and some 3-inch AA guns - plus accommodation for around 230 RN personnel and the essential 1500 to 3000 tons of ballast. Second-stage conversion included some 1-inch thick armour plate, more modern guns and director firing (in just nine ships). Brown says that, later, empty oil drums were packed in the 'tween decks "to preserve buoyancy and stability' and he comments that this was so successful that of the 15 AMCs sunk, only one capsized. As readers will be aware capsize is a frequent result of a torpedo hit even on major warships such as HMS Royal Oak, HMS Barham or HMS Ark Royal. Just one in 15 losses therefore represents some considerable vindication of the heavy ballasting if not of the oil drums themselves. I assume from his phrasing that the oil drums were the third-stage so, in addition to availabilty, one has to factor-in the estimated 10 weeks it would take to do that work (see previous paragraph for time-to-completion).
On page 167 Brown reveals that the torpedoed (not lost) AMC HMS Cheshire was able to make six knots with two main holds flooded and a third slowly flooding. She got home successfully and was repaired in the remarkably short time of six weeks. Brown also reveals that the oil drum expedient was actually incorporated into the design of the Colossus Class light aircraft carriers. It would be interesting to know if these oil drums remained in the post-war Colossus Class when they served in the navies of France, Holland, Australia, Canada, Argentina and Brazil and whether they were still there when these venerable ships went to the breakers' yard. I wonder what the crew made of them?
That the oil drums came as a surprise to the Germans is discussed by Chris Paddock on his Patroclus and Laurentic website:
sites.rootsweb.com/~cannf/mil_hmspatlau.htm
"U-99 closed to within 300 yards without being spotted, and fired a torpedo, which struck Patroclus near the stern, immediately beneath a loaded lifeboat that was being hauled aboard. The lifeboat, the men aboard it, and a huge section of Patroclus' hull were blown to pieces. Kretschmer and his officers were astounded to see a large number of empty oil drums erupt from the ship's newly torn hull to bob like corks on the ocean swell. U-99 then fired another torpedo at the same section of Patroclus' hull."
Later...
"A large section of the forward well deck disintegrated, and several of Patroclus' crew vanished into the smoking void. Another volley of escaping oil drums confounded the U-boat's commander, and Kretschmer concluded, correctly, that they had been placed in Patroclus' hold in order to sustain the ship's buoyancy and survivability in the event of a torpedo attack. He further concluded that Laurentic's reluctance to sink was likely due to the same reason."
And...
"Otto Kretschmer, while returning U-99 to her patrol area, recorded in his log the curious use of the empty oil drums, stacked by the hundreds in the holds of the armed merchant cruisers, as a torpedo countermeasure. Ultimately it didn't save the ships, but it did force him to exhaust the lion's share of his torpedo supply to sink them. He would record a very similar incident less than a month later, when, on December 2nd, he attacked and sank another armed merchant cruiser, H.M.S. Forfar. Her holds were also jammed with oil drums, and it took 5 torpedoes to sink her."
Chris Paddock's whole page is worth a very careful read is it reveals that Otto Kretschmer had to carry out the double attack on Laurentic and Patroclus with a loitering Sunderland above him and a nearby enemy destroyer heading towards him.
While researching this I also had access to 'The Blockaders' by A Cecil Hampshire. On page 38 he confirms that timber and empty metal drums had already been added to RN AMCs in WW1 as a direct result of the clash between the AMC HMS Carmania and the German Cap Trafalgar in 1914.
Author Hampshire also refers to the oil drums and ballast, implying that all ships were outfitted with the oil drums which - as we have seen - is probably unlikely. He says the drums were: "Officially designated buoyancy ballast but dubbed by the crews 'ping-pong' balls to help keep the ship afloat in the event of her being torpedoed or mined."
Reviewing the evidence it is fairly clear that while the Admiralty AMC was clearly an extemporised warship and suffered from all the faults of being just that - extemporised. There was a high survival rate among the crews serving on them coupled-with the ability of several of the AMCs to absorb more torpedo hits than some WW2 battleships (HMS Royal Oak and HMS Barham were each sunk by only three torpedoes). All seamen love their little jokes but the 'Admiralty-Made Coffins' may be worthy of rather more respect, in hindsight, than they ever received during the war.
